Thin wall tubing furniture structure



' July 16, 1968 w. o. KELIEHOR THIN WALL TUBING FURNITURE STI RUCTUREFiled Oct. 19. 1965 2 Sheets-Sheet 1 INVENTOR. Mu MM D. Kat/1402 July16, 1968 w. D. KELIEHOR I THIN WALL TUBING FURNITURE STRUCTURE 2Sheets-Sheet Filed Oct. 19. 1965 MM W115, Kaua /0e Y jaw: 1% m UnitedStates Patent 3,392,947 THIN WALL TUBING FURNITURE STRUCTURE William D.Keliehor, 11 Nishi Bayashi-cho, Shimogamo, Sakyo-ku, Kyoto, Japan FiledOct. 19, 1965, Ser. No. 497,940 21 Claims. (Cl. 248188.1)

ABSTRACT OF THE DISCLOSURE A joint system for furniture utilizing flatsided tubing or channel frame members. Each joint is clean and alljoining surfaces are flush since the tubing used for the joint housingis of the same size and shape as the tubing used for the frame membersbeing joined. Flat sided stubs with outside dimensions approximatelyequal to the inside dimensions of the frame and housing tubes areinserted into and extend from the ends of and apertures formed in thestraight joint housings. The other ends of the stubs are inserted intothe ends of the frame members meeting at the joint.

This invention relates to joint structures and to frame constructionsemploying the same, and is herein illustrated in its application to anarticle of furniture, such as includes legs or uprights, and sets ofupper and lower frame members interconnecting the legs. While theinvention is herein illustratively described by reference to thepresently preferred embodiment thereof, it will be recognized thatcertain variations and modifications thereof may be made withoutdeparting from the essential features involved. A stool has been chosenas a representative application for the invention, but the inventioncould be incorporated in a coffee table, or in an end table, or in morecomplex designs, whether for furniture or for other use to which it isadapted.

Such articles of furniture must support a load and be capable ofresisting racking torques. This would normally require the use of tubingor other frame member that are thick-walled or heavy, if fabricatedaccording to ordinary techniques. Desirably, such articles should be oflight weight, however, and by the principles of this invention they canbe made such by advantageous employment of thin-walled tubular material,brass for example, and yet by the use of joints which in themselves area part of the invention, and by the manner of joining the frame membersto these joints, according to the invention, the article can be madeadequately strong and rugged, yet light in weight, and attractive atrelatively low cost by employment of structural members any prefinish ofwhich remains unmarred by the processes of fabrication into a completedstructure.

Wherever joints are required in such thin-walled tubing members, theheat associated with Welding or brazing tends to warp and distort themas well as to preclude use of prefinishes applied to the tubularmembers. Moreover, grinding and polishing of weld or braze seams is timeconsuming and expensive, and tends to dull any bright finish. Accordingto the present invention joints in thin wall tubing structures areadvantageously achieved without such difficulties by a novel techniqueinvolving cutting, interfitting and bonding with cold-set or lowtemperature materials applied to the frame members and joint stubcomponents used therewith in the novel manner hereinafter described.While the invention is not limited to particular bonding agents, epoxyresin, or if preferred silver solder, are the presently preferredexamples.

It is also an object hereof to devise improved joint structuresemploying thin wall tubular members, all exposed parts and surfacesbeing inconspicuously joined flush in contiguous relationship so as toafford an attrac- 3,392,947 Patented July 16, 1968 tive structure whichis easily and quickly assembled and in which, through a system of mutualabutment of parts and joined surfaces, the members serve to brace oneanother and avoid the need for external welds or brazing to achievestructural rigidity.

It is also an objective hereof to provide thin wall tubing structuresthe parts and fittings of which may be provided in assembly kit form,precut and prefinished, convenient for shipping and storage yet capableof being assembled readily and quickly, and if desired, permanently,although similar principles will apply if the structure be arranged tobe knocked down after having been once assembled.

This invention comprises novel joint constructions for rectangular thinwall tubular articles, articles incorporating interconnected tubularmembers having such joint structures and the several individual jointstructure embodiments comprising the presently preferred means forpracticing the inventive concepts to achieve the above and relatedobjects.

FIGURE 1 is primarily a phantom isometric view of the illustrativestool, illustrating in particular several of the joint structures of theinvention.

FIGURE 2 is an isometric view of a joint structure according to theinvention, for joining three frame members each at a right angle to theother two, and FIG- URE 3 is a sectional view longitudinally of the samejoint structure, at the line 3-3 of FIGURE 2.

FIGURE 4 is an isometric view of a joint structure according to theinvention, for joining two frame members meeting at a right angle, andFIGURE 5 is a longitudinal section of the same, at the plane indicatedby the line 5-5 of FIGURE 4.

FIGURE 6 is an isometric view, showing a variation of the jointstructure of FIGURE 2.

FIGURE 7 is an isometric view of a joint structure used in cross-bracingthe piece of furniture, wherever this is required.

In the illustrative stool shown in FIGURE 1 uprights or legs 91 arejoined at their upper ends with rails 92, 93 that define a square orother form of rectangle, and are joined at their lower ends byhorizontal floor-engaging bars 94. The form of the joints will bedescribed below. The cushion 9, of any suitable form, rests upon thesquare 92, 93, and in particular in the form shown, upon the rails 93 ofthat square. The cushion could, of course, be so formed as to besupported also, or instead, by the rails 92, but as shown these rails92, which lie in a plane somewhat above the rails 93, serve as stops toprevent lateral shifting of the cushion.

The simplest form of joint structure is that which joins tworectangularly related frame members, such as an upright 91 and a bar 94.This joint structure is shown in detail in FIGURES 4 and S. It includesa sleeve or housing 1, of the same tubular material as the frame membersthe same in cross section and in wall thickness, and normally of thesame color and finish. If of polished brass, a thin, hard transparentplastic coating is usually applied as a prefinish to protect the lustreof the metal. This housing is closed at one end, as by a silver solderedor epoxy resin bonded end cap 10 of the same material, but is open atits opposite end. Immediately above the end cap 10 a side wall 11 isapertured, and a stub 2 of a cross section less than that of the tubularmember 94 by the thickness of the opposite side walls of the latter, isreceived within such aperture, and projects laterally from thehousing 1. The stub 2 can be, but it need not be, tubular, with fourwalls, but it is preferably channel-shaped, open at one side. Both thetubular member 94 and the stub 2 have flat sides, that contact oneanother. Thus, the stub has two opposite walls 20 which contact theinside of the opposite walls 12 of the housing 1, and it is of lengththat its squared inner end abuts the wall 13 opposite the aperture.Desirably, also, its lower margin, the edges of the channel as shown,engage the end cap 10. The contacting walls 20 and 12, or at least oneof them, are joined permanently, as by silver soldering or by a strongadhesive such as epoxy resin. The ends of the stubs channel, where theyabut the inside of walI 13, may be similarly joined, as may also theedges of the channel 2 and the end cap 10. To insure penetration of thejoining agent between the walls, the entering portion of the stub 2 maybe scored or striated; this has not been illustrated in order to avoidconfusion.

Next a second stub 3, of like cross section as the stub 2, is fittedwithin the open end of the housing 1, and projects therefrom. It, too,is shown as of channel shape, and its Walls 30 contact and are joined tothe inside of walls 12 of the housing, and its wall 31 to the inside ofwall 11. It is not strictly essential that all these walls bepermanently joined, as long as one wall is so joined. The stub 3 is of alength that its squared end abuts the inner end face 21 of stub 2, andso reinforces the latter and locates it fixedly in position.

Now the upright tubular frame member 91 fits onto the stub 3, and itssquared end lies flush against the end of housing 1. The bar 94 fitsonto the stub 2, and its squared end lies flush with the side walls 11and 1'2 of the housing. Parts can be secured in this relation in anysuitable way. If they are to be disassembled later, bolts receivedwithin nuts aifixed inside the stubs 2 and 3 may be used to join them.No such bolts and nuts are shown, because they can be joined permanentlyif this be required, such as with silver solder or epoxy resin or otherlow temperature bonding agent, application of which will not warp nordistort the prefinish of the members.

The joint structure of FIGURES 2 and 3 is similar to that of FIGURES 4and 5, but is intended for use at the upper end of an upright 91. Itprovides a third stub 4 located longitudinally intermediate stubs 2 and3, and extending at right angles to the plane defined by these twostubs, to receive a frame member such as 93, whereas at this locationstub 3 fits upright 91 and stub 3 receives rail 92. The stub 4 is fixedwithin the housing 1 in the same manner as is stub 2. It is located justenough below the level of stub 2 that when frame members 93 and 92 arefitted to the respective stubs and their ends abut the housing 1, theupper surface of member 93 is flush with the lower surface of member 92,and the latters upper surface is flush with end cap 10. Joining orabutting side surfaces of frame members 92 and 93 are flush with likesurfaces of the housing 1. The result is a pleasing, unitary appearance.

FIGURE 6 illustrates a modification of the joint of FIGURES 2 and 3, inthat the housing 1 extends above the level of frame member, and isclosed at its upper end by a large end cap 10a, from which depends astub 10b fitting within the open upper end of housing 1. The end cap 10ais provided with apertures 10c whereby the top 9 can be secured in placeby screws or bolts.

A cross-bracing joint is shown in FIGURE 7. It would be used wheneverthe cushion or top 9 requires additional support centrally, or elsewherebetween its sides. It includes a tubular housing 1a, apertured betweenits ends at two opposite side walls 11a. A stub 5 extends through thehousing side walls 11a, and projects at each side of the housing In. Itsupper wall, in the arrangements shown, contacts the inside of the upperwall of housing 1a, and can be fixed thereto in the manner alreadydescribed. Stubs 6a and 6b enter the open ends of housing In, and abutthe stub 5, bracing the latter. These stubs 6a and 6b are similarlyfixed in place within the housing 1a. All these stubs, in the formshown, define a common plane. Matching stubs (not shown) are supportedon the marginal frame members, in similar fashion, and tubular struts 7aand 7b are fitted onto such stubs and onto the stubs 6a, 6b, and 7a, 7b,respectively, and are secured I 4 thereto, flush with the housing 1a andwith the frame members. This afiords additional center support withoutchange in the basic arrangement of the stool, and without great addedweight.

It will be clear that the rectangular tubular members used might differin cross section and still achieve flush joints using the invention,provided that they have one equal cross-sectional dimension. As in theusual connotation the term rectangular includes the case of a square asWell as the general case. These and other aspects of the invention willbe recognized by those skilled in the art referring to the withindisclosure of the presently prefered embodiments.

I claim as my invention:

1. A framework for furniture or the like, comprising uprightrectangular-section tubular frame members 91 and transverse tubularframe members 92 of like cross section extending in angular relation toone another, and

a joint structure 1 at points where they meet including a straighttubular housing 1 of substantially the size and shape of said members,

a first stub 3 received within an end of said housing 1, and of a sizeand shape and formed with at least two flat walls to contact flatwiserespectively at least two flat inside walls of said housing 1,

at least one such fiat wall of the stub 3 being fixedly joined to thecorresponding inside wall, and the stub being of a length to projectfrom said housing 1 and to fit closely within an end of a first framemember 91, in contact with at least two inside walls thereof to extendthe length of said frame member 91 by the length of said housing 1,

said housing 1 having an aperture in its side wall for a further framemember 92 which it joins, to receive a further stub 2,

such further stub 2 being of a size and shape defining at least two flatwalls to contact two corresponding fiat inside Walls of the housing 1,and fixedly joined to at least one such inside wall, and of a length toproject from the housing 1 and to fit closely within the end of saidfurther frame member 92, in contact with at least two inside wallsthereof.

2. A framework as defined in claim 1, wherein the stubs and the housingare complementally of a size and channel shape, the opposite side wallswhereof contact flatwise the opposite housing, and are fixedly adheredat each such point of flatwise contact.

3. A framework as defined in claim 1, wherein the tubular frame members,the housing, and the stubs are all effectively of substantially squarecross section.

4. A framework as defined in claim 1, wherein the housing of the jointstructure at points where three frame members meet, has a secondaperture in a side wall at right angles to the first-mentioned aperturedwall, and offset lengthwise from the first aperture, and a further stubentering the second aperture and of a size and shape to define at leasttwo flat walls, to contact flatwise the two corresponding respectivefiat inside walls of the housing, and fixedly joined to at least onesuch inside wall, and of a length to project from the housing and to fitclosely within the end of a third frame member, in contact flatwise withat least two side walls thereof.

5. A framework as in claim 4, wherein the upper end of the housing isspaced above the upper frame member, and an end cap secured thereto andoverlying and projecting outwardly of the housing, and formed forsecurement thereto of an overlying support.

6. A framework as in claim 1, wherein the end of each tubular framemember abuts and is flush with the corresponding portion of the housing.

7. A framework as defined in claim 1, including a cross-bracingstructure joining two pairs of opposite parallel frame members that aredisposed at right angles to one another, between their ends, saidcross-bracing structure including a central crossing element and fourstruts joined thereto at their inner ends and joined at their outer endsto the respective parallel frame members by joint structures as definedin claim 1, the crossbracing structure comprising a rectangular-sectiontubular housing apertured at its opposite sides between its ends, a stubextending through said opposite apertures and formed with two flat wallsrespectively contacting fiatwise two corresponding flat inside walls ofthe housing, and joined to at least one such inside wall, said stubbeing of a size and shape to fit its projecting ends closely within theinner ends of two opposite struts, in contact with at least two insidewalls of said struts, and a stub received within and projecting from theopposite ends of the housing and at their ends contacting the throughstub, said last-mentioned stubs being of a size and shape to define atleast two flat walls to contact the corresponding inside flat walls ofthe housing, at least one such stub wall being fixedly joined to itscontacting housing wall, and of a size and shape to fit closely withinthe inner ends of the other two opposite struts, in contact with atleast two inside walls thereof.

8. A joint structure for use in joining two rectangularsection tubularframe members of furniture or the like which meet at an angle, saidjoint structure comprising a straight tubular housing of a size andshape corresponding to the frame members that are to be joined, a firststub received within an end of said housing, and of a size and shape todefine at least two flat walls to contact flatwise at least two flatinside walls of the housing, and fixedly joined to at least one suchinside wall, said stub being of a length to project from the housing andto fit closely within an end of one of the frame members to be joined,in contact flatwise with at least two fiat walls thereof to extend thelength of said frame member by the length of said housing,

said housing having an aperture in a side wall to receive a secondlaterally directed stub,

said second stub being of a size and shape to contact flatwise at leasttwo fiat inside walls of the housing, and fixedly joined to at least onesuch inside wall, and

said second stub being of a length to project laterally from the housingand to fit closely within the end of and in contact flatwise with atleast two flat walls of a second of the frame members to be joined.

9. A joint structure as defined in claim 8, including a closure fittedto and joined to the end of the housing opposite the first stub, thesecond stub contacting and braced by said end closure, and the firststubs end engaging and bracing said second stub.

10. A joint structure for use in joining three rectangular-sectiontubular members of furniture or the like, two of which meetsubstantially at a right angle and a third of which meets substantiallyat a right angle to the plane defined by the first two, said jointstructure being adapted for inner position between and junctured to thethree frame members, and comprising a straight rectangular-sectiontubular housing of a size and shape corresponding to the frame membersthat are to be joined,

a first stub received within an end of said housing and of a size andshape to define at least two flat walls in flatwise contact with thecorresponding two inside walls of the housing, and fixedly joined to atleast one of such fiat inside walls,

said first stub being of a length to project from the housing and to fitclosely within an end of a first frame member, in flatwise contact withat least two flat inside walls thereof to extend the length of saidframe member by the length of said housing,

said housing having an aperture in one such wall to receive a secondstub,

said second stub being of a size and shape to contact flatwise at leasttwo flat inside walls of the housing, and fixedly joined to at least onesuch inside wall, and of a length to project laterally from the housingand to fit closely within the end of a second frame member, in flatwisecontact with the corresponding two fiat inside walls thereof,

said housing having a further aperture in a different side wall, offsetlengthwise from its first-mentioned aperture, to receive a third stub,

said third stub being of a size and shape to contact flatwise at leasttwo flat inside walls of the housing, and fixedly joined to at least oneof such inside walls, and of a length to fit closely within the end ofthe third frame member, in flatwise contact with the corresponding twoflat inside walls thereof.

11. A joint structure as in claim 10, wherein the end of the housing isspaced above the upper frame member, and

an end cap secured within such upper end of the housing and projectingmarginally outwardly thereof,

said projecting marginal portion being formed for securement thereto ofan overlying support.

12. A cross-bracing structure for use in cross-bracing a tubularframework such as includes two pairs of opposite parallel frame membersthat are disposed at right angles to one another, said cross-bracingstructure comprising a central crossing element and four struts forjoining to the parallel frame members at their outer ends and joined tothe crossing element at their inner ends,

said central crossing element comprising a straight rectangular-sectiontubular housing of a size and shape corresponding to said frame membersapertured at its opposite sides between its ends,

a stub extending through and projecting from said apertures and formedwith at least one flat wall fixedly adhered to at least one fiat insidewall of the housing, and of a size and shape to fit closely within theinner ends of two opposite struts, in flatwise contact with at least twoflat walls thereof, and

a stub received within and projecting from the opposite ends of thehousing, and each at its inner end contacting the through strut, and ofa size and shape to fit closely within the inner ends of the other twostruts, and also to define at least two flat walls to contact flatwiserespectively at least the corresponding flat inside walls of thehousing, and at least one stub wall being fixedly adhered to thecorresponding housing wall.

13. A joint structure for use in joining two tubular frame members ofrectangular cross section, for furniture or the like, and which meet atan angle, said joint structure comprising a straight rectangular housingof a size and shape corresponding to the frame members that are to bejoined,

a stub received within the side wall at an end of said housing, of asize and shape to contact at least two flat inside walls thereof, andfixedly adhered to at least one such inside wall,

one wall of said housing being apertured for entrance of the stub andthe stub being of a length to project laterally from the housing and tofit closely within and at least against two fiat side walls of an end ofone of the frame members to be joined, and

a second stub of a shape and size to fit within the end of said housing,in contact with at least two flat inside walls thereof, and fixedlyadhered to at least one such inside wall,

said second stub being of a length to project from the end of thehousing and to fit closely within and against at least two fiat sidewalls of the end of a second of the frame members to be joined to extendthe length of said frame member by the length of said housing.

14. A joint structure as defined in and for the purpose specified inclaim 13, wherein the inner end of the second stub contacts the outerwall of the first stub.

15. A joint structure as in claim 13, wherein the inner end of the firststub contacts the inner wall of the housing, opposite the lattersaperture.

16. A framework for furniture or the like, comprising upright tubularframe members of rectangular cross section, and like transverse tubularframe members arranged in rectangular relation, a joint structure ateach point where two or more such frame members meet, said jointstructure in its form where three frame members meet comprising ahousing of a cross section corresponding to that of the frame members, astub directly laterally in one direction from the end of said housing,the latters Wall being apertured to receive said stub, and the stubbeing of a size and shape to contact flatwise at least two inside wallsof the housing, and joined to a least one such inside wall, and also ofa size and shape to contact endwise at least two inside walls of thehousing opposite its aperture, said stub also being of a size and shapeto engage closely within at least two walls inside the end of anotherframe member, a further stub offset lengthwise of the housing from thefirst stub, and similarly engaged with and projecting from a secondapertured wall of the housing, and similarly engaged within the end of adifferent frame member, and a third stub received within and projectingfrom an end of the housing, and at its end abutting one of the otherstubs, and joined to a side wall of the housing, said third stub beingof a size and shape fitting closely within the end of a still furtherframe member, in engagement with at least two fiat inside walls thereof.

17. An article of furniture as in claim 16, including a cross-bracingstructure interconnecting the two members of each of the two oppositepairs thereof, between their ends, said cross-bracing structureincluding a central tubular element of rectangular cross section havingfour stubs projecting laterally towards each of the paired framemembers, complimental stubs projecting laterally from each such framemember towards the corresponding central stub, and four tubular strutsof rectagular cross section fitting closely about and contacting twofiat walls of each of the two corresponding stubs, and abutting at itsends the frame member and the central element.

18. A framework for furniture or the like, comprising upright tubularframe members of rectangular cross section, and like substantiallyhorizontal tubular frame members arranged in rectangular relation,

a joint structure at each point where two or more such frame membersmeet,

said joint structure in its form Where only two frame members meetcomprising a straight tubular housing of a cross section size and shapecorresponding to that of the frame members,

a stub directed laterally in one direction from the end of said housing,the latter being apertured to receive closely said stub, and the stubbeing of a size and shape to contact fiatwise at least two inside wallsof the housing, and joined to at least one such inside wall, and tocontact endwise the inside Wall of the housing opposite its aperture,

said stub being also of a size and shape engaging closely within atleast two walls inside the end of one frame member, and

a second stub received within and projecting from an end of the housing,and at its end abutting the first stub, and joined to a side wall of thehousing,

said second stub being of a size and shape fitting closely within theend of the second frace member, in engagement with at least two insidefiat walls thereof to extend the length of said second frame member bythe length of said housing.

19. A framework for furniture or the like, comprising:

four tubular frame members effectively of rectangular cross section,

two of said members in use are disposed in parallelism in a commonplane, and the other two in parallelism transverse to the first two in acommon plane offset from the plane of the first two, and

a joint structure at points Where said frame members intersect includinga tubular housing of substantially the size and shape of said framemembers, which in use is disposed perpendicularly to and intersects theplanes defined by said frame members,

said housing having an aperture in at least two relatively angularlydisposed side walls thereof,

each aperture of a size and shape to receive a stub,

said apertures being offset lengthwise of said housing in correspondencewith the offset of said planes defined by the respective frame members,and

stub means received within each aperture,

each stub being of a size and shape forming at least two fiat exteriorwalls to contact two corresponding fiat inside walls of said housing,and fixedly joined to at least one such inside wall, and of a length toproject from said housing and to fit closely within the end of thecorresponding frame members,

such frame member ends contacting and lying flush with the side walls ofsaid housing.

20. A joint structure for use in joining two rectangular-section framemembers or the like which meet substantially at right angles to oneanother, said joint structure comprising:

a tubular housing of a size and shape corresponding to the frame membersthat are to be joined,

said housing having an aperture in a side wall of a size and shape toreceive a first stub that extends laterally beyond such side wall to fitwithin the end of a frame member,

a second aperture in a side wall of said housing angularly related tosaid first-mentioned side wall,

said second aperture of a size and shape to receive a second stubsimilarly extending laterally at an angle to said first stub to fitwithin the end of a second frame member,

said two apertures being offset relatively lengthwise of said housingsuch that the stubs when thus received into said housing contact oneanother and are thereby braced one from the other.

21. A joint structure as in claim 20, including:

an end closure fitted to and joined within the end of said housing,

said end closure being of a length to contact and brace the stub whichis nearer to such housing end, and through that stub to brace the otherstub.

References Cited UNITED STATES PATENTS 2,546,187 3/1951 Harward287189.36

FOREIGN PATENTS 793,017 11/1935 France.

252,490 10/1948 Sweden.

CHANCELLOR E. HARRIS, Primary Examiner.

